Film casting compositions and method of making same



miware ers of vinyl aromatic com- ;mniugated aliphatic dlolefines in disonasolidsurface, of dryingto form compositions provided by the infilms which adhere tightly to most ,c. g. of wood, paper, cloth, masonry,

on which they are cast and which they are applied. The! are useful tions which may be m ifi Mdltion agents to form paints. t solutions of copol s of tie compounds and aliphatic conjua i ways of forming such soluknown. In general, the solutions as e. g. in the manufacture of an emulsifying agent, and usually an M storage or use. A variety of emulsifyanti-oxidants for use in such soluwe also known. Examples of such emulsia. are sodium oleate, sodium stearate, ID iasodium sulphate ester of higher l and sodium sulphonates of alkylated biphenyls, etc. Examples of antiwhich may be employed are aromatic polyhydric phenols, and aldeand aliphatic conj ted such as the previously known solutions .when applied as a thin film to a and permitted to dry, either fail to I mlidualcontinuous film of the copolymm acopolymer film having properties for protective coating purposes. is of the copolymers having less than v per cent of dioleiine in the copolymer based on the combined amount of polyllllterlals of which the copolymer is M to form a continuous copolymer which solutions have the property,

,sn STATES PATENT OFFICE mas css'rnic oourosrrrons moon or sumo sum animating-newts ma man-stomps: a...

Midland. Oomoil)- N Drawing. Application! same,

mam-1i 12 Claims. zoo-saw) 2 more than 56 mole per cent of ,diolefine chemically combined in the polymer molecule frequently a form continuous copolymer films when spread on a solid surface and dried, but the copolymer films bbsr, comprise water, the dispersed to stabilise the copolymer against thus produced are soft, tacky, easily marred, and do not adhere well to the surfaces on which they are formed. iln copending applications of E. L. l'iedler, Serial No. 879,879,,flled June 27, 1946, and L. L. Ryden, Serial No. 679,877, filed June 2'7, 1946, it is disclosed that continuous tack-free films of resinous or rubber-like material may be cast directly from aqueous colloidal solutions of certain of the oopoLvmers, containing between 40 and 56 mole per cent of a chemically combined dioleflne. However, even in these instances the film-forming properties of the solutions, or the quality of the films produced, may be improved by modifying the solutions in accordance with the present invention. In general, the tendency toward formation of continuous films on drying such aqueous copolymer dispersions becomes greater with increase in the proportion of diolefine chemically combined in the copolymers. Although the copolymer films formed from solutions of the copolymers containing more than 56 mole per cent of chemically combined diolefine are unsatisfactory for the reasons just mentioned, they certain desirable properties, i. e. they are quite fiexible and elastic and the tackiness thereof indicates a tendency toward formation of a bond with solids contacted therewith, even though the bond is not as strong as desired.

On a basis of these observations, we formed an opinion that the tackiness and other undesirable properties of the cast fllmsof copolymers rich in a dioleilne were due largely to a fairly high degree of residual unsaturationin the copolymer molecules and that it might be possible to discover agents which would further saturate the polymers without impairing their useful properties. It was thought that the objectionable characteristics of the fihns might thereby be overcome and the desirable properties be retained. Although this theory is believed to have been sound, it has not fully been substantiated and the inventions is not restricted thereto. However, the purposes then in mind have been accomplished to a degree greater than was contemplated.

, Among the agents tested which might react with the copolymers to further saturate the latter were drying oils and unsaturatedderlvatives thereof. It was found that, by dispersing a drying oil material in an aqueous colloidal solution of such copolymers containing from 25 to 66 mole per cent of diolefine chemically combined in the poly- 3 mer molecules, compositions were obtained which could be applied to solid surfaces, e. g. of paper,

cloth. wood, or metal, etc., and dried to leave a I tightly adhering uniform continuous film of the copolymer. Since such addition of a drying oil permitted casting of continuous films from aqueous colloidal solutions which, except for the addition, would not form continuous films and since it also resulted in formation of non-tacky films from aqueous polymer solutions which would otherwise form tacky films, it is evident that the drying oil performs a plurality of functions. Among the useful functions which it appears to perform are those of reacting with the copolymer to further saturate the latter, of plasticizing the copolymer, and of increasing the film forming characteristics over those possessed by the dispersed copolymer itself.

Drying oils have proven effective in producing film casting compositions when added to aqueous colloidal solutions of copolymers of monovinyl aromatic compounds and aliphatic coniugated diolefines containing from 25 to 66 mole per cent of diolefine chemically combined in the copolymer and they are also effective in instances in which a considerable part, c. g. as much as two-thirds on a mole ratio basis, of the vinyl aromatic compound employed in the copolymerforming reaction is replaced by other polymerizable unsaturated organic compounds such as methyl methacrylate, vinyl chloride, or vinylidene chloride, etc. In most instances, drying oils are not satisfactorily eifective in forming film casting compositions when added to aqueous colloidal solutions of such copolymers containing a chemically combined diolefine in proportions outside the limits just expressed. Drying oils are also not satisfactorily effective for the purposes of this invention when added to natural rubber latex. It appears that the degree of unsaturation of the polymer molecules in natural rubber latex and in aqueous colloidal solutions of the above-mentioned copolymers containing more than 66 mole per cent of a diolefine is too great to be satisfactorily overcome by addition of a drying oil, i. e. even though a drying oil be added to thesesolutions prior to spreading and drying the same, tacky films of poor quality are usually obtained. It also appears that the plasticizing action and film-forming characteristics of a drying oil are insufilcient to overcome the hard, brittle characteristics of the aforementioned copolymers containing less than 25 mole per cent of a chemically combined diolefine, so that even though a drying oil be added to an aqueous dispersion of such copolymer, the resultant composition does not dry to forma tightly adhering continuous film of good quality.

The minimum proportion of drying oil to be added to an aqueous colloidal solution of the aforementioned copolymers varies somewhat with changes in the kind of drying oil employed and the proportion of chemically combined diolefine in the copolymer, but is in all instances sufilcient to produce a continuous film upon spreading and drying the resultant composition. In most-instances, a drying oil is added in amount corresponding to between 25 and 100 per cent of'the weight of the diolefine-containing resin which is to be modified therewith.

When using a given proportion of a drying oil, the properties of the final film vary with change in the proportion of diolefine chemically combined in the dispersed copolymer with which the drying oil is admixed. In general, the films become somewhat softer, more flexible and more elastic with increase in the proportion of diolefine in said copolymer from to 66 mole per cent of all polymerizable organic compounds of which the copolymer is composed.

Within the limits just given, the kind and proportion of drying oil. and the diolefine content of the lymer treated with the oil. are varied in ace dance with the properties desired in the final films. For instance. when an aqueous emulsion of the copolymer is to be applied to form a protective or decorative coating on wood or masonry, a fairly hard film resistant to marring is usually desired, but it is not of importance that the protective film be highly fiexible and elastic. In such instance the proportion of drying oil is restricted so as not to exceed greatly that necessary for formation of a continuous film and the dispersed copolymer treated with the oil may advantageously contain only a limited amount of diolefine, e. g. an amount corresponding to from 25 to 55 mole per cent of all polymerizable organic compounds chemically combined in the copolymer. 0n the other hand, when a material such as paper or cloth is to be treated with the colloidal solution, it may be of prime importance that the protective coating formed thereon be highLv flexible and quite elastic. A film having such properties may be obtained from an aqueous dispersion of a copolymer containing 40 mole per cent or more of chemically combined diolefine, which dispersion has been treated with a relatively large proportion of a drying oil, e. g. from 0.6 to 1.5 parts by weight of the oil per part of the copolymer with which it is admixed.

Examples of copolymers formed entirely or principally of a vinyl aromatic compound and an aliphatic conjugated diolefine and suitable for employment in practice of the invention are copolymers of styrene and butadiene-1,3 of styrene and isoprene; of 4-chlorostyrene and butadiene- 1,3; of 4-chlorostyrene and isoprene; of 3-chlorostyrene and butadiene-1,3; of 2-chlorostyrene and butadiene-1,3; of butadiene-1,3 and a monoethyl-styrene containing the ethyl radical as a nuclear substituent; of styrene, butadienel,3 and vinyl chloride; of styrene, butadiene-1,3 and vinylidene chloride; or of styrene, butadiene-l,3 and methylmethacrylate, etc., provided the copolymers contain from 25 to 66 mole per cent of diolefine chemically combined with the other polymerizable organic compounds. Copolymers of styrene and butadiene and also of styrene, butadiene and vinylidene chloride are preferably used.

Any of the usual vegetable drying oils such as linseed oil, tung oil, oiticica oil, or dehydrated castor oil, etc., can be employed. Unsaturated copolymers of drying oils, which copolymers undergo oxidation on exposure to air,'e. g. drying oil-modified alkyd resins or copolymers of drying sion in a closed container, usually at temperatures 4 between 50 and C. to eifect polymerization.

to be P 7 the polymerlntion, the

ittodry.asolid.'non-tacky conis formed on the treated suriaceipartbyweilhtoidrylneoilmateto be'treated therewitmbut the dryxmmlslmaybeuedinnnallerorgreater dllmaterialoontaininganemulsitymaybeaddeddirectlytotheaqueous ii the latter is sufliciently composition maybe appliedin g.b iieuhing.diwi r myas paper. cloth. wood, plaster,

toiormatizhtlyadherreeiniilmonthe surfaces Prior to such application a resinsuchasrosinmaybedismtiiemistureiormirposeotincreasing iormeduponspreading and drymaorwhiteleadetcsmayalsobe the aqueous colloidal solution of v anddryingoiltoiormem water as a liquid medium. Paints mannn'spreadwellanddryrapidly so i coatings oi good apmple! whichdeecrlbeeresultsobtained castreslnomdhnsdirectlyfrom solutionsoicopolymersoisiwor copolymers oi styrene. lideneohlorlde, ispresented mice 0 action. Inmostinstanceepotassiumpermlphate wasalsoinitiallyaddedinamountcorresponding toaboutmipercentoithecombinedweightoi the compounds to bepolymerised. Aiter completingthepolymeriltiomthevesselwascooled. opened. andthe resultant aqueous colloidal solution oi the oopolymer was removed. The solutiomthus prepared contained about40percent byweightoicopolymerindispersediorm. lach solution was applied as a layer oi approximately 0.02 inch thickness to a glass plate. The layers were dried. first at room temperature until apparently free of water and thereafter at 70 C. for

mqnployedperpartoithedispereed aboutshourssoastoassuresubstantiallycomplete removal oi moisture. The residual deposits of copolymeric material were examined. The iollowingtable identifies each copolymerby naming and giving the relative proportions of the polymerimble compounds employed in iorming it. The table also describes the polymer residues obtained by and drying the colloidal copolymer solutions.

Table I Run Dried 0 Buta- Vin lidene fi'zr' diene, chime,

PC cent Mob Mob Per Cent Per Cent l .9 48.1 Opaque powder. 2 48.8 00.2 A but clear. colt,

lexib ,rubbery iilm. 8 14.8 85.2 A tacky, but clear, soft,

rubbery film. 4 56.0 3.5 13.5 Opequepowder. 6 40 88.5 21.5 Abardopaqueiilmwbieh o a an Illa A out aw m- 1 n1 01.0 1.s Do. l 30.0 06.7 18.7 A tacky, translucent rubbery Example 2 In each of a series of experiments, an aqueous colloidal solution, containing about 40 per cent by weight oi a dispersed copolymer of styrene and butadiene, or of styrene, butadiene and vinylidene chloride. was prepared by procedure similar to that described in Example 1. Aqueous emulsions of drying oils, or drying oil copolymers which retain drying properties, were prepared by adding a drying oil, or such copolymer, to an equal weight of an aqueous solution containing 2 per cent by weight oi water-soluble methyl cellulose, 4 per cent of the 2-amino-2-methyl-propanol salt of oleic acid as an emulsifying agent. 0.04 per cent of cobalt naphthenate and 0.5 per cent of lead naphthenate. Such naphthenates are well known paint driers. The mixtures were agitated to effect emulsiiicatlon. To an emulsion of the drying oil. or drying oil copolymer, a colloidal solution of a butadiene-contalnlng copolymer was added in measured amount. In some instanoestherewasatendeneytowardcoagulation of the butadiene-containing oopolymer'during admixtures with the drying oil emulsion. in which case soluble methyl cellulose was added to the butadiene-containing copolymer solution in amount corresponding to 2 per cent of the weight of the copolymer prior to continuing addition of the same to the drying oil emulsion. Stable colloidal dispersions oi a butadiene-containing copolymerandadrylngoiLordryingoilcopolymer havine drying properties, were thereby 8 composition. The table also 1 7 Each composition obtained.

prepared from such On. a

cast as a layer of about ess, and, in-the instances ey were dete glass plate and permitted to dry, first at room temperature until apparently free of water and ed, gives the tensile grams-per square centimeter and inkilo thereafter at 70 C. for about 3 hours. In each there remained on the per cent elongation value of the dried film. The per cent its initial le of this series of experiments elongation value is the per cent of. ngth by which a film may be elongated the glass plate a tightly adhering, non-tacky, continuous film of resinous material.

The thickness of each dried film was measured. In certain I I under tension before breaking Table II V- 0 0 1 6 n k 0 a IL t e 0 0mm 0 mm m m mm wm mm m m 1 a a a m a N mm 0 0: M mm mme 0 0 .mmmm .w mm. 1% M m 0 0 0% 0 M MM 1 0mm 0M1 M m? 1 m 1m 0.0 0 W M1 mm mfim mm e v. w. v.u v. ,1 v. bd w GB on 0 00 0 0 00 .0 m mfnw m mm 0 0 m 0 mnmmm w r e wmmm m v .mmmmmm 0 00 m 1 0mm 1 01 0 mm. .0 000. wo .1 .0 m m a m m va mmm a 0 ayfiw a 1% v 1 1" y mnfum m. w m mw .0. M m m 0 0010 .0 0 0 was A as 0 1 0 0 A 00.....0. 1 W0... 0 M. .W w. m M mymw v. mmmm my .WYWW. v Mm v. MmY v. MWYWW 3 mm fimm a m e t u .1 ..1fl1 1fl.11 ofl1 fl fl fl 1H o -1 H" U 1. a. .00 $0 0 mmuammmamwflmamm 00000000000000 am wfimmamwmamm m m 0 0 0.0 0 m0 0 n as a o kahuna am muhha u umuu a esmm a mums a n u m m W11 n do. A AA AA A AAAAAA AAA AAAA A AAAA A AAA A AAAA A AAAAA m w m m mmmm mm I I 1I. I 1I. I on m mm m mm a mmm m m m mmm mmm mmmm m mm mmm I "m s I I E m m mmw amm mw m0 I I I 1 0 0.1 0. 1%. PE I I I II I m mwwmmmm m m an m m 0.1.1.000 mean 00 0 ass 01.0 0 0 sum 0 1 001 0 m I e m mmm mm a a 2 0100 0.1.0" I 0 I :3 m fmmmm m 1 aw I Iw x wmw w w mIIuwI n i mmw m mm m m mmmmmmmmmmm I mm m mmm mmmm m mmm mwmm I m m I I A m n m m wd FT 0 00 0 0 00000000000 I. 0 0 we 0 0 0 0000 0 0 0 0 0 0 00 m m m0 0 m .I mmmu w m MM mw m H mm mwmm mmimmmmmm mm wmwm mwm wmmw m mml mmwmmw mm mm mw w m M .wO Br..S.eegmm fimm mwmmmmm 0 or r "0 I I n I 1" I mmak mwm m% m m MM m I I I mm I I m mmwmm mnmmm a m m e I m I I u AW y 1 m 0 HT M d mm I m II m." I M m to m mt m mm 10m M. II II d m :m m n ude m m m0 mv0 0 mm 00 m0 0 0 0 0 0 0 0 s? 0 0 0 0 m mmse uwmm m1 100 .0101 0 0 .0 0 000 M m mm m m b V. mm a M mcA I m II M m I mm mm m awmwww m m0 0 m I 1111111 11 .11 1 .111 .1 mmnm md omm d 5 607777333311 5 7 3 310 7733 87 1778& e e F. .l. n m c O n M m 1 13 1122 1% 1 123 1 l 2 11 mv mm w o mmmw m e wn s mm 1 c v I mmm g wmm m f 0 1 .1 1 .1 .00 .11 0 001 1 .0 .1 1 0 .1 mu mm trnm mmmm 1 mm ammo whmammwwwwwn was new 0000s 0 a ma ma as 000% m mam nmmdw 0 m mh ty c t m 1 t ta 0 g h n n m 0 1 11 1 .11 .01 .01 .00 0 wm m m m m a so one mnwwmmfimm 00. on. 0.0.00 0 mwmmwmm m w a l f 1 m n e mammmfs m m h mm o m I II II I mm u m m. I I II I III or u n u R 1 2 0 1 0 0 1 his was .0. mmwmabwmmmabmm 9 mmlultaut mixture oi 0.02 per cent by weight mt. 0.02 per cent of manganese and 0.5 0 cent cilead. To the mixture there was added l 715 grams oi an aqueous solution a copolymer composed of 43.8 mole per and 56.2 mole per cent butadiene. thereby obtained a white paint which thinned to suitable consistency with waa tightly adhering paint film of high The him is satisfactorily resistant to' both while dry and when wetted with miter modes of applying the principle of the lemma may be employed instead oi those exchance being made as regards the methobmpositions herein disclosed, provided the i or ingredients stated by any or the folclaims or the equivalent oi such stated or ingredients be employed.

More particularly point out and disas ourinvention: 1 u A coating composition consisting essentially W M aqueous colloidal solution of one part by 01' a polymer. comprising a monovinyl WWW: compound, of the class consisting of v i aromatic hydrocarbons oi the benzene nuclear monochlorinated monovinyl hydrocarbons oi the benzene series, and Hit aliphatic conjugated dioleiine, oi the class i i ct butadiene'and lsoprene, in chemicombined form, the dioleiine being in mmut corresponding to between 25 and 66 mole Mt oi all monomeric polymerizable organic of which said polymer is composed, more than 1.5 parts by weight oi a drying tsrial selected from the class consisting oi drying oils and unsaturated polymers \MM from vegetable drying oils and havingthe m w or undergoing drying by oxidation upon M corresponding to between 25 and 100 per M the weight of the dioleiine-containing coating composition. as described in claim wherein the dioleiine-containing polymer is a 0 comprising styrene and butadiene in combined form. t y t. A coating composition, as described in claim i the dioleflne-containing polymer is a l of styrene and butadiene and the dryoll material is present in amount correspond- WM copolymer.

ill coating composition, as described in claim M which! the dioleflne containing polymer is a 1 of styrene, butadiene and vinylidene amuse compositiomas in claim mm the dioleiine-containing polymer is a mtbbstweenfl and 100 per cent or the weight 10 chloride and the drying oll material is present in amount corresponding to between 25 and 100 per cent oi the weight of said copolymer.

'7. A paint consisting essentially of an aqueous colloidal solution of one part by weight of a polymer comprising a monovinyl aromatic compound, oi the class consisting of monovinyl aromatic hydrocarbons of the benzene series and nuclear monochlorinated monovinyl aromatic hydrocarbons of the benzene series, and an allphatic conjugated dioletlne, oi the class consisting of butadiene and isoprene, in chemically combined form, the diolefine being in amount corresponding to between 25 and 66 mole per cent of all monomeric polymerizable organic compounds of which said polymer is composed, between 0.25 and 1.5 parts by weight of a vegetable drying oil, and a pigment.

8. A paint, as described in claim 7, wherein the vegetable drying oil is present in amount corresponding to between 25 and 100 per cent'of the weight of the dioleflne-contalning po ymer.

9. A paint, as described in claim 7, wherein the dioletlne-containing polymer comprises styrene and butadiene.

10. A paint, as described in claim 7, wherein the dioleflne-containing polymer is composed of styrene and butadlene and the vegetable drying oil is present in amount corresponding to be tween 25 and 100 per cent of said polymer.

11. A paint, as described in claim 7, wherein the diolenne-containing polymer is a copolymer oi styrene, butadiene and vinylidene chloride and the vegetable drying oil is present in amount corresponding to between 25 and 100 per cent of said copolymer.

l2. Amethod of making a coating composition which comprises admixing with an aqueous colloidal solution of a polymer comprising a monovinyl aromatic compound, of the class consisting of monovinyl aromatic hydrocarbons oi the bensene series and nuclear monochlorinated monovinyl aromatic hydrocarbons oi the benzene series, and from 25 to 66 mole per cent of an aliphatic conjugated dioleflne, oi the class consisting of butadiene and isoprene. in chemically combined form, a drying oil material selected irom the class consisting of vegetable drying oils and unsaturated polymers derived from vegetable drying oils and having the property oi undergoing drying by oxidation upon exposure to air, the drying oil material being in amount not exceeding 1.5 parts by weight thereoi per part of the polymer derived from the vinyl aromatic compound and dioleilne, and suflicient to produce a continuous iilm upon spreading and drying the coating composition.

I ARTHUR 1:. rooms.

K. STILBKRT.

REFERENCES CITED The following references are of record in the tile oi this patent: 

